Where to find old knob types?

[Ghitza]

Hi guys,
are there places where you can buy this type of precision knobs for multi turn potentiometers with 3mm shaft diameter?
Thank you!

[bdunham7]

You need all the exact dimensions, number of turns etc.

At first glance, this might work.

https://www.newark.com/bourns/h-516-3a/turn-counting-dial-satin-chrome/dp/75T9977

[radiolistener]

are there places where you can buy this type of precision knobs for multi turn potentiometers with 3mm shaft diameter?

like this one?
https://www.aliexpress.com/item/32846199722.html

[TimFox]

Make sure your shaft size is 3 mm, not 1/8 in = 3.18 mm (another common size) before buying the knob.

[Ghitza]

Thanks for the reply guys but none of those is what I search. It is written on it this:
"MOD 20 DIGITOOL BIENNE SWISS".
The diameter is 20.4mm and 21.2mm long. The axis diameter is exactly 3mm and it came with a 3540S-ZMX-502 5K Bourns 10 turn potentiometer.
This knob can do 20 turns. I like because it is very small comparing to the knowbs made for 6mm and uper axis.
I did a search for this potentiometer and there is absolutelly no information for it. It was recovered from a Philips PM3219.

[wizard69]

There are literally hundreds of variations here so finding something that fits exactly might be an issue.   For example this: https://www.nteinc.com/pot_web/pdf/400_500_Series.pdf, is close but would require a shaft bushing.    Here is another close fit: https://www.ttelectronics.com/TTElectronics/media/ProductFiles/Turn%20Counting%20Dials/Datasheets/2600.pdf, again requiring a shaft bushing.   

You could try these guys:

• http://www.kilointernational.com/ as they seem to specialize in smallish knobs and dials.
• https://www.bourns.com/products/potentiometers/turns-counting-dials
• https://www.ohmite.com/assets/docs/acl_acd22.pdf 
•  

The problem of the potentiometer shaft might not be as big as you might think.   The shaft can be easily bushed and that is done frequently.   The bigger problem is actually mounting the new control.   As you know space is tight, beyond that you need the right bore for the mounting nut and correct alignment of the back plate.    You will have to look at the cad drawings to determine if a specific knob will fit.

Best of luck!    It looks like those small controls are hard to find these days.